Tracking pixel

A tracking pixel is a 1×1 pixel graphic embedded in a web page or email that records an action when it loads. The technique is also called pixel tracking. The image is usually transparent and invisible to the reader. Marketers use tracking pixels to count page visits, measure conversions, and see which emails are opened.

How a tracking pixel works

The pixel is hosted on a server rather than inside the page or email itself. When someone opens the page or message, their browser or email client requests that image from the server. The request carries information the server can log, such as the time, the device and the IP address. Nothing appears on screen, which is why tracking pixels are also called invisible pixels or web beacons.

How tracking pixels differ from cookies

Tracking pixels are often compared to cookies, and the two work differently. A cookie is a small text file stored on the visitor’s own device. A tracking pixel stores nothing on the device: it makes a request that the server records. That difference matters when a browser blocks cookies, because a pixel can still fire.

Where tracking pixels are used

Pixels appear across the web as well as in email. Advertising platforms use conversion pixels to attribute a sale to the ad that led to it. Retargeting pixels show ads to people who have already visited a page.

Social networks offer their own versions, such as the Meta pixel and the LinkedIn Insight Tag. Email platforms use a simpler version, covered in the next section.

What an email tracking pixel does

An email tracking pixel is the same technology applied to a message rather than a page. Your email platform adds the image to the HTML before sending. When the recipient’s email client loads images, the pixel fires and the open is recorded.

A tracking pixel measures opens only. Clicks are tracked separately, by rewriting each link so it passes through the sending platform before reaching its destination. The two are usually grouped together as open and click tracking, but only one of them uses a pixel.

Why open rates are not exact

Open tracking depends on images loading, so it undercounts. Many email clients block images by default, and the open is never recorded. Apple Mail Privacy Protection goes the other way by loading images for every message, which inflates the figure. Treat open rate as a directional signal rather than an exact count.

Consent rules for tracking pixels

Regulators in the EU increasingly treat an email tracking pixel as something that needs the recipient’s consent. The reasoning is that the pixel reads or stores information on the recipient’s device, which brings it under ePrivacy rules as well as GDPR. France’s CNIL set out that position for email in 2026, and Italy’s Garante reached a similar view.

Mailjet’s Email Tracking Consent and Anonymous Tracking features respond to this. Recipients set their own tracking preference, and campaign reporting continues without tying opens to a named contact. Our guide to tracking pixels and EU regulators covers what changed and what it means for senders.

How to create a tracking pixel

Most senders never create one. Any established email platform adds the tracking pixel automatically when open tracking is switched on. Building one by hand means hosting a 1×1 image, adding a unique identifier for each recipient, and logging every request. Mailjet’s email tracking tools handle that automatically.

Common questions about tracking pixels